Understand bladder cancer

Bladder cancer was the sixth most common cancer in the United States in 2021, but was the fourth most common cancer diagnosed in men.

The information on this page may help you gain a better understanding of your bladder cancer diagnosis and what’s happening to your body. This may help when making important decisions with your doctor.

What is bladder cancer?

What Is Bladder Cancer?

Bladder cancer is a disease in which malignant (cancer) cells form in the tissues of the bladder.

Most bladder cancers start in the innermost lining of the bladder. There are other types of cancer that start in the bladder, but they are much less common.

The risk of bladder cancer increases with age; 90% of people with bladder cancer are over the age of 55, and the average age at the time of diagnosis is 73.

Men are 4 times more likely to develop bladder cancer than women.

Types of bladder cancer

Urothelial carcinoma, or transitional cell carcinoma, is the most common type of bladder cancer.

Urothelial carcinoma begins in cells in the innermost tissue layer of the bladder. These cells are able to stretch when the bladder is full and shrink when it is emptied. Most bladder cancers begin in the transitional cells.

There are a few other types of bladder cancer, but these are less common:

  • Squamous cell carcinoma: cancer that starts in the bladder lining because of irritation or inflammation
  • Adenocarcinoma: cancer that starts in the glandular cells
  • Small cell carcinoma: cancer that starts in nerve-like cells called neuroendocrine cells
  • Sarcoma: cancer that starts in the fat or muscles of the bladder

Stages of bladder cancer

From the National Cancer Institute (NCI)

The information below is based on information originally published by the National Cancer Institute (NCI), the government’s main agency for cancer research, and is meant to be a general guide. Use this information to talk to your doctor about your specific stage of bladder cancer.

Bladder cancer is categorized in 5 stages ranging from 0 to IV (4), with stage IV (4) being the most severe. Some stages can also be broken down further into substages (A or B).

Stage 0 bladder cancer

In stage 0, abnormal cells are found in tissue lining the inside of the bladder. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 bladder cancer, also known as non-muscle invasive bladder cancer, is divided into stages 0a and 0is, depending on the type of the tumor:

  • Stage 0a is also called noninvasive papillary carcinoma, which may look like long, thin growths growing from the lining of the bladder.
  • Stage 0is is also called carcinoma in situ, which is a flat tumor on the tissue lining the inside of the bladder. These cancers are very abnormal and often grow quickly. 

Learn about a possible treatment option for certain patients with non-muscle invasive bladder cancer who meet specific criteria.


Stage I (1) bladder cancer

In stage I (also known as non-muscle invasive bladder cancer), cancer has formed and spread to the layer of connective tissue next to the inner lining of the bladder. This means that the cancer hasn’t grown into the muscle wall.

Learn about a possible treatment option for certain patients with non-muscle invasive bladder cancer who meet specific criteria.


Stage II (2) bladder cancer

In stage II, cancer has spread to the layers of muscle tissue of the bladder.


Stage III (3) bladder cancer

Stage III is divided into stages IIIA and IIIB.

In stage IIIA

  • cancer has spread from the bladder to the layer of fat surrounding the bladder and may have spread to the reproductive organs (prostate, seminal vesicles, uterus, or vagina) and cancer has not spread to lymph nodes;

Or stage IIIA can be

  • cancer has spread from the bladder to 1 lymph node in the pelvis that is not near the common iliac arteries (major arteries in the pelvis).

In stage IIIB

  • cancer has spread from the bladder to more than 1 lymph node in the pelvis that is not near the common iliac arteries or to at least 1 lymph node that is near the common iliac arteries.

Stage IV (4) bladder cancer

Stage IV is divided into stages IVA and IVB.

In stage IVA

  • cancer has spread from the bladder to the wall of the abdomen or pelvis;

Or stage IVA can be

  • cancer has spread to lymph nodes that are above the common iliac arteries (major arteries in the pelvis).

In stage IVB

  • cancer has spread to other parts of the body, such as the lung, bone, or liver.

Learn about a possible treatment option for patients with advanced bladder cancer who meet certain criteria.